The use of IVOMEC (R) (ivermectin) Pour-On and permethrin ear tags for horn fly control

The effect of spring and mid-summer application of IVOMEC(R) Pour-On in con junction with moderately effective (permethrin) ear tags on horn fly popula tions was studied at four sites in Louisiana in 1994 and at four sites in A labama in 1995. Spring application of IVOMEC Pour-On alone resulted in sign ificantly fewer (p<0.05) horn flies compared with untreated controls throug h week 5 in 1994, and through week 8 in 1995. Spring application of IVOMEC Pour-On in conjunction with permethrin ear tags resulted in significantly f ewer horn flies compared with untreated controls at weeks 1 through 5 as we ll as in weeks 7, 9 and 11 in 1994, and week 1 through week 11 in 1995. Spr ing application of permethrin ear tags alone resulted in significantly fewe r horn flies compared with untreated controls at weeks 7 and 9 in 1994 and week 1 through week 10 in 1995. Mid-summer application of IVOMEC Pour-On, w ith or without application of ear tags in the spring, resulted in significa ntly fewer horn flies compared with untreated controls for 4 weeks post-tre atment in 1994, and for 5 weeks post-treatment in 1995.